Olmsted County, Minnesota: septic system inspection at sale
Checked on November 9, 2026 against the official rule. Rule set by Olmsted County.
General information, not legal advice. This is our summary of the official rule as we read it. The ordinance or code and the health department decide: confirm with them before you list, sign or close.
The rule
| Question | What the official text says |
|---|---|
| What is required | County Land Transfer Compliance form: all SSTS owners complete and file a Compliance Inspection 'prior to the transfer of property'. Source: olmstedcounty.gov |
| Triggered by | transfer Source: olmstedcounty.gov |
| Deadline | Compliance inspection filed prior to transfer; report to buyer before closing; form signed by Planning Dept presented at transfer to Property Records Source: olmstedcounty.gov |
| How long a report is valid | State default: 3 years (existing system), 5 years (new/replacement); county text may differ Source: revisor.mn.gov |
| Who may inspect | Minnesota Pollution Control Agency (MPCA) licensing of SSTS businesses. official list (webapp.pca.state.mn.us) Source: webapp.pca.state.mn.us |
This is our summary of the official rule as we read it. The ordinance or code and the health department decide: confirm with them before you list, sign or close. Rule set by: Olmsted County.
Checked on November 9, 2026: read on the official site.
Septic systems in Olmsted County: the state’s count
MPCA counts 15,997 septic systems (SSTS) in Olmsted County in 2025, the 12th highest number of Minnesota’s 87 counties. Licensed inspectors and the county did 136 compliance inspections of existing systems that year: 0.9% of the county’s systems, against 2.11% statewide (the 65th highest share). The county issued 162 construction permits in 2025 and 3,323 from 2002 to 2025. MPCA’s table marks the county as requiring a compliance inspection at property transfer, which matches the rule on this page. The county figures include the city and township septic programs inside it (MPCA footnote).
Source: MPCA, 2025 Subsurface Sewage Treatment Systems Annual Report (April 2026), Appendix A, as reported by each county; ranks among the 87 counties in the table (1 = highest). MPCA counts all compliance inspections of existing systems, whatever the trigger (property transfer, building permit and others).
Private wells in Olmsted County
In 2015 about 20,826 of Olmsted County’s 151,436 residents (14%) got their drinking water from a private well, by the USGS estimate. That is the 79th highest share of the 87 Minnesota counties in the USGS table, and the 17th highest number of private-well users.
As we read it, this rule covers the septic system, not the well.
Source: USGS county water use 2015 (Dieter et al., 2018). Ranks count the Minnesota counties in the USGS table (1 = highest).
Soils and septic systems here
USDA soil surveys rate 93% of Olmsted County’s rated land “very limited” for a conventional septic drain field, 7% “somewhat limited” and 0% “not limited”, the 62nd highest “very limited” share of 85 Minnesota counties with survey data. The most common limits: slow percolation (dense or clay soil) on 85%; a high water table (saturated soil near the surface) on 35%; fast seepage below the field (risk to groundwater) on 22%.
Where soils are limited, inspections more often find drain fields that sit in seasonally wet soil, and replacement systems are often mounds or other engineered designs. A county-wide rating, not a test of one lot: a site evaluation decides. Source: USDA NRCS Soil Survey Geographic Database (SSURGO), via Soil Data Access, rating “ENG - Septic Tank Absorption Fields”, read November 15, 2026.
Certified labs nearest to Olmsted County for a well water test
Labs on the Minnesota certified drinking-water list that the list marks as taking samples from homeowners or outside clients, certified for coliform bacteria, nearest first. 1 of them is in Olmsted County.
| Lab | Town | Distance | Certified on the list for |
|---|---|---|---|
| Southeastern Minnesota Water Analysis Laboratory | Rochester, MN · in this county | under 1 mile | coliform bacteria, nitrate, arsenic (subcontracted) |
| Fillmore SWCD Water Quality Laboratory | Preston, MN | 30 miles | coliform bacteria |
| Red Wing City Laboratory | Red Wing, MN | 38 miles | coliform bacteria |
Source: MDH Accredited Labs in Minnesota Accepting Drinking Water Samples from Private Well Users (October 2026; read November 15, 2026). Straight-line distance from the centre of Olmsted County (the average of its Census ZIP-area points); “approx.” = lab placed at its ZIP centre. Call the lab first: lists do not say which household tests each lab takes or what it charges.
Nearest other sale-time rules
Buying or selling near a county line? These are the closest other local rules in our census to Olmsted County.
| Rule | State | Distance | Covers | Checked |
|---|---|---|---|---|
| Dodge County | Minnesota | about 21 miles | Septic system | November 9, 2026 |
| Mower County | Minnesota | about 29 miles | Septic system | November 9, 2026 |
| Goodhue County | Minnesota | about 29 miles | Septic system | November 9, 2026 |
| Fillmore County | Minnesota | about 31 miles | Septic system | November 9, 2026 |
| Steele County | Minnesota | about 40 miles | Septic system | November 9, 2026 |
Straight-line distance between county centres (the average of each county’s Census ZIP-area points). Townships, villages and health districts are placed at the centre of their county.